This is fast paced, high velocity, can't-put-down action at the top of its game.
Court Gentry is a former CIA operative who is now an assassin for hire. He is working for a Russian mafioso, Sidorenko, a man he doesn't like and doesn't trust. Gentry's assignment is to assassinate the Sudanese President, but the CIA offer him amnesty in exchange for kidnapping rather than assassinating the President - a task that seems near impossible. Most of the book is set in the Sudan, a brutally harsh and challenging environment. At one point the author references the military expression "Black Hawk Down" and there are strong elements of that film in parts of this book.
"On Target" follows on from The Gray Man
, but it's sufficiently stand alone that you don't need to have read the predecessor. In fact it's a better book: more tightly plotted, more credible and with virtually no let up in action. Gentry makes occasional errors of judgement that add significantly to the tension. As in the first book, he's a highly skilled operative, but one with emotional baggage and flaws.